Intel
®
81341 and 81342—Address Translation Unit (PCI Express)
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
262
Order Number: 315037-002US
3.6
PCI Express Messages
PCI Express defines a new message mechanism that is used to communicate outside of
the normal Memory, I/O, and Configuration Spaces. The messages received and
initiated by 81341 and 81342 vary depending on whether the device is acting as a root
complex or an endpoint. All the messages defined in the PCI Express* specification and
81341 and 81342’s actions are listed in
.
Table 121. Supported Message Types (Sheet 1 of 2)
Message
Description/ Comments
RC or
End
Point
Comment
Standard Messages initiated by SRL
ERR_COR
Signal detection of a correctable error
to Root Complex
RC, End
Point
Set appropriate bit in ATUISR
RC: Also log in PCI Express Error
Source Identification Register
ERR_NONFATAL
Signal detection of an uncorrectable
error Root Complex
ERR_FATAL
Signal detection of a fatal error Root
Complex
PM_Active_State_NAK
Rejection of request to enter a low
power state from an End Point or
Upstream Port.
RC
PME_Turn_Off
a
Notification of pending turn-off of link
clock and power
RC
Generated from PEMCSR.
PM_PME
b
PME message conveying the ID of the
PME originator
End
Point
PME_TO_Ack
Acknowledge turn-off of link clock and
power
End
Point
Automatically generated on
receipt of PME_Turn_Off
message
Assert_INTx
Assert INTx virtual signal
End
Point
Generate to reflect signals from
Interrupt Controller.
Deassert_INTx
De-assert INTx virtual signal
End
Point
Set_Slot_Power_Limit
Set Slot Power Limit in Upstream Port RC
Generated due to write to Slot
Capabilities register or anytime
Link transitions from non-DL_Up
status to a DL_Up status.
Vendor Defined Message
Type 0/1
Vendor Specific Message. It is used by
devices to communicate with SRL
device core.
RC,
End
Point
Generated from Outbound
Vendor Message register.
Attention_Indicator_X
These messages are issued by the
root port to change the indicator on
the device
RC
Generate due to change in
indicator control bits in Slot
Control Register
Power_Indicator_X
These messages are issued by the
root port to change the indicator on
the device
RC
Attention_Button_Pressed Issued by endpoint when button
pressed on device
End
Point
Generated from PEMCSR